Young women in South Africa better off with daily PrEP

03 November 2017

Young, sexually active women at high risk of HIV in South Africa more likely to take PrEP daily over other time or events-based methods new study finds.

A clinical trial reveals young South African women at high risk of HIV infection are more likely to adhere to daily doses of oral pre-exposure prophylaxis (PrEP) over other methods where PrEP is taken less regularly, or taken as events-based.

The HPTN 067/ADAPT study, the first to compare daily and non-daily combination oral PrEP use among African women, found participants were more likely to be able to adhere to and benefit from PrEP’s preventative effect when on a daily regime. It provides important insight into an HIV prevention method that finally gives control to women who may experience difficulty negotiating condom us.

A total of 191 heterosexual women with a median age of 26 took part in the trial, which ran between 2011 and 2012. Participants came from the Crossroads Township near Cape Town, where HIV prevalence among women is estimated to be as high as 29%. Although transgender women were eligible, all women included were cis-gendered.

For the first five weeks, all participants took PrEP once a week. After this, participants were split into three random groups. For the next six months, the first group took PrEP daily, the second group took it twice-a-week and within two hours of having sex (described as ‘time driven’ dosing), and the third group took one tablet up to 48 hours before anticipated sex and two hours after it (described as ‘event driven’ dosing).

The study found that, although more pills were required for the daily PrEP doses, 75% of women adhered to this type of regime, compared with 65% of those using the time-driven approach, and 53% of those taking it before and after sex. Results were similar across younger and older participants.

In addition, PrEP’s protective coverage in relation to specific occurrences of sex was significantly higher among those taking PrEP daily. When sex was reported in the previous week, PrEP drugs were detected more frequently in women assigned the daily regimen (68%) than in those allocated the time-driven regimen (58%) and the event-driven regimen (41%). Interestingly, women on the daily regimen reported almost double the occurrences of sex compared to those on the time-driven regimen.

Incomplete coverage was mostly due to missed post-sex doses, which were more common among those taking non-daily dosing regimens. This is largely due to the fact that daily dosing meant women did not need to forecast sex or actively take a dose after sex when they were more likely to be resting or asleep.

Similar to earlier trials, researchers found side effects of PrEP were uncommon and restricted to the first few weeks of use. This adds further reassuring data to the safety profile of PrEP.

The trial’s results also suggest that ensuring the delivery of PrEP to women at risk of HIV could be vital in eliminating the long-standing disparity in HIV infection rate between genders in sub-Saharan Africa, where an estimated 1.4 million new HIV infections in 2015 alone occurred among young women.